Halogenated phosphonoacetate esters

ABSTRACT

MONOHALO AND DIHALOPHOSPHONOACETATE ESTERS HAVING THREE HYDROCARBYL GROUPS CONTAINING FROM 5 TO 7 CARBON ATOMS, USEFUL AS EXTREME PRESSURE ADDITIVES IN LUBRICANT COMPOSITIONS, ARE DISCLOSED.

United States Patent 3,649,722 HALOGENATED PHOSPHONOACETATE ESTERS Denzel Allan Nicholson, Springfield Township, Hamilton County, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio No Drawing. Continuation-in-part of applications Ser. No. 762,966, Sept. 26, 1968, Ser. No. 770,860, Oct. 25, 1968, and Ser. No. 785,740, Dec. 20, 1968. This application Jan. 29, 1969, Ser. No. 795,039

Int. Cl. C07c 9/40; ClOm 1/46 US. Cl. 260 941 Claims ABSTRACT OF THE DISCLOSURE Monohalo and dihalophosphonoacetate esters having three hydrocarbyl groups containing from 5 to 7 carbon atoms, useful as extreme pressure additives in lubricant compositions, are disclosed.

CROSS REFERENCES This application is a continuation-in-part of the copending application of Robert Earl Wann, Denzel Allan Nicholson, and Ted Joe Logan, Ser. No. 762,966, filed Sept. 26, 1968, for Lubricant Composition, and of the copend ing application of Denzel Allan Nicholson, Ser. No. 770,- 860, filed Oct. 25, 1968, for Process for the Production of Halogenated Methylenediphosphonates, Malonates and Phosphonoacetates, and of the copending application of Denzel Allan Nicholson, Ser. No. 785,740, filed Dec. 20, 1968, for Halogenated Phosphonoacetate Esters.

FIELD OF THE INVENTION This invention relates to certain monoand dihalogenated phosphonoacetate esters, which contain 1 or 2 chlorine, bromine, and iodine atoms attached to a bridging carbon connecting a phosphonate ester moiety and a carboxylate ester moiety, useful as extreme pressure additives in lubricant compositions.

PRIOR ART The copending US. application of Curry, Ser. No. 770,- 805, filed Oct. 25, 1968, for Hypohalogenation of Tetramethyl and Tetraethyl Methylenediphosphonates and Trihydrocarbyl Phosphonoacetates, discloses a process for the preparation of halogenated trihydrocarbyl phosphonoacetate esters wherein the hydrocarbyl groups contain from 2 to 4 carbon atoms.

The copending application of Denzel Allan Nicholson, Ser. No. 770,860, filed Oct. 25, 1968, for Process for the Production of Halogenated Methylenediphosphonates, Malonates, and Phosphonoacetates, discloses halogenated trihydrocarbyl phosphonoacetate esters wherein the hydrocarbyl groups have from 8 to about 22 carbon atoms and a process for their preparation.

Accordingly it is an object of this invention to provide phosphonoacetate esters wherein the hydrocarbyl groups have from 5 to 7 carbon atoms.

SUMMARY OF THE INVENTION This invention relates to monoand dihalogenated trihydrocarbyl phosphonoacetate esters which are useful as 3,649,722 Patented Mar. 14, 1972 extreme pressure additives in lubricant compositions. The monoand dihalogenated trihydrocarbyl phosphonoacetate esters (hereinafter called halogenated phosphonoacetates or phosphonoacetate esters) of this invention have the formula DESCRIPTION OF THE INVENTION The halogenated phosphonoacetate esters of this invention have the formula wherein each R is a hydrocarbyl group selected from the group consisting of alkyl, alkenyl, haloalkyl, haloalkenyl, aryl, alkaryl, aralkyl, haloary, haloalkaryl, haloaralkyl and nitroaryl groups having from 5 to 7 carbon atoms, wherein each X is selected from the group consisting of hydrogen, chlorine, bromine and iodine, and wherein both Xs are not simultaneously hydrogen.

R in the above formula is a hydrocarbyl group. Examples of suitable hydrocarbyl groups for R are follows: alkyl groups such as Z-methyl, pentyl, hexyl, heptyl and iso-pentyl; alkenyl groups such as pentenyl, hexenyl and heptadienyl; haloalkyl groups such as chloropentyl, 3-fluoro-2-methylbutyl, bromoheptyl, iodohexyl, 2-chlorohexyl, 2,2-dibromopentyl, 1-chloro3-iodohexyl, and 7,7,7- trichloroheptyl; haloalkenyl groups such as iodopentenyl, 2-chloro-3,3-dibrorn0hexenyl, and 7 chloro-7-bromo-7- iodoheptenyl; aryl groups such as phenyl; alkaryl groups such as methylphenyl; aralkyl groups such as benzyl; haloaryl groups such as chlorophenyl, 3,5-dichlorophenyl, bromophenyl, iodophenyl and 2-chloro-4-iodophenyl; haloalkaryl groups such as (chloromethyl)phenyl, (iodomethyl)phenyl, (bromomethyl)phenyl, and (bromoiodomethyl)phenyl; and haloaralkyl groups such as o-chlorobenzyl; and nitroaryl groups such as nitrophenyl. It is preferred that R be an alkyl group, preferably pentyl, hexyl and heptyl because of their ready availability.

As has been hereinbefore described, X in the above formula can be hydrogen or a halogen atom such as chlorine, bromine or iodine. Bromine is preferred. Where one X is hydrogen and the other X is a halogen atom the monohalogenated phosphonoacetate esters are described; where both Xs are halogen atoms, the dihalogenated phosphonoacetate esters are described.

Examples of novel trihydrocarbyl halogenated phosphonoacetate esters of this invention are given in the table below.

Dihalcgenated phosphonoacetate esters Trihexyl diiodophosphonoacetate.

3-chloropenty1-2ehlorohexylheptyl dichlorophosphonoacetate.

Trlpentyl monoiodophosphonoacetate. 2-fluoropentyl-2-chloropentyl-2' bromopentyl monohromophosphonoacetate. Hexyl(methyl)butyl-1so-pentyl monochlorophosphonoacetate. Iso-pentylhexenylbenzyl mono- Di-iso-pentylpentyl dibromo phosphonoacetate. Di (6,6-difluorohexyl) ('bromo) dienyl monoiodophosphonoacetate. Triphenyl monobromophosphono- Tribenzyl monobromomonoacetate. iodophosphonoacetate. Tribenzyl monolodophosphono- Tripentyl monobroruornonochlorophosphonoacetate.

ac e.

Benzyl(methyl)phenyl-o-chlorobenzyl ehlorophosphonoacetate.

(Chloro) phenyldiphenyl monoiodo- Triphenyl dibromophosphonoacetate. Benzyl(rnethyl)phenyl(chlorophosphonoacetate. methyDphenyl diiodophosphonoacetate. 2,4-diehlorophenyldlbenzyl Trl(chlorophenyl) dlbromomonobromophosphonoacetate. phosphonoacetate.

Pentyl(chloromethyDphenylbenzyl monolodophosphonoacetate.

2-fiuoropentyl-o-chlorobenzyliodophenyl monobromophosphonoaeetate.

3-chloropentenyl-o-bromobenzylphenyl dichlorophosphonoacetate.

The novel monoand dihalogenated phosphonoacetate esters of this invention, examples of which are shown above, can be prepared according to the process described by Oscar T. Quimby and James B. Prentice, in US. patent application, Ser. No. 770,782, filed Oct. 25, 1968, for Hypohalogenation of Gem-Diphosphonate Esters and Phosphonoacetate Esters. This application is incorporated herein by reference. The process described therein can be used to prepare either the monoor the dihalogenated phosphonoacetate esters wherein the hydrocarbyl groups have from 5 to 7 carbon atoms.

In the process described in Quimby et aL, supra, the monohalogenated phosphonoacetate ester is prepared by hypo-halogenating a phosphonoacetate ester according to the following equation:

In the above equation OX represents a hypohalite ion; X is a chlorine, bromine, or iodine atom; M is an added electrolyte; and R is as hereinbetore defined.

The hypohalite reactant used in Equation I above to form the monohalogenated phosphonoacetate ester is depicted simply as OX, rather than as an inorganic hypohalite compound. The hypohalite reactant can be introduced into the reaction system as an inorganic hypohalite such as NaOBr, NaOCl, NaOI or other equivalent alkali metal or alkaline earth metal forms. Alternately the hypohalite ion can be generated in situ. Normally the monohalogenated phosphonoacetate ester is prepared using from about 0.7 to about 1.5 moles of hypohalite ion to 1 mole of phosphonoacetate ester. Molar equivalency of the two reactants, e.g., '1 mole of hypohalite ion to 1 mole of phosphonoacetate ester, generally results in a. high yield of the monohalogenated compound.

The dihalogenated trihydrocarbyl phosphonoacetate ester can also be prepared by a second embodiment described in Quirn'by et al., supra, in which the process for the preparation of the monohalogenated trihydrocarbyl phosphonoacetate ester in Equation I above is continued to produce the corresponding dihalogenated trihydrocarbyl phosphonoacetate ester, In this process the monohalogenated phosphonoacetate ester obtained according to Equation I is hypohalogenated to produce the corresponding dihalogenated trihydrocarhyl phosphonoacetate ester. The production of the dihalogenated phosphonoace- 4 tate ester according to this process is described by the following equation:

(In M,H2O

RgPO CXHCO2R OX R2P03CX2CO2R OH- where R, X, OX- and M are as hereinbefore described.

In order to provide sufficient hypohalite ion to form the dihalogenated trihydrocarbyl phosphonoacetate ester, i.e., by hypohalogenation of the phosphonoacetate ester to produce the dihalogenated phosphonoacetate ester, a large excess of hypohalite ion is used, for example, from about 2 to about 2.5 moles of hypohalite ion per 1 mole of phosphonoacetate ester. From the standpoint of economy about 2.05 to about 2.1 moles of hypohalite ion are generally used per 1 mole of phosphonoacetate ester in the formation of the dihalogenated trihydrocarbyl phosphonoacetate esters.

The dihalogenated trihydrocarbyl phosphonoacetate ester can also be prepared according to the process described by Equation II by beginning with the monohalogenated phosphonoacetate ester obtained from any source, i.e., from the process described by Equation I, or any other suitable reaction wherein the monohalogenated phosphonoacetate ester is produced. Where the monohalogenated phosphonoacetate ester is used as the starting material high yields of the dihalogenated phosphono acetate ester can be obtained by using from about 1 to about 1.5 moles of hypohalite ion per 1 mole of monohalogenated phosphonoacetate ester and preferably from about 1.05 to about 1.1 moles of hypohalite ion per 1 mole of the monohalogenated phosphonoacetate ester.

It will be appreciated that where a two-step process is used, e.g., the preparation of the monohalogenated phosphonoacetate ester (Equation I) and subsequently the dihalogenated phosphonoacetate ester (Equation II), it is possible to prepare dihalogenated phosphonoacetate esters wherein the halogens substituted on the bridging carbon are different. For example a monochloro trihydrocarbyl phosphonoacetate ester can be prepared according to Equation I and subsequently reacted with additional hypobromite or hypoiodite according to Equation II to form a trihydrocarbyl chlorobromophosphonoacetate ester, R PO CBrClCO R, or a trihydrocarbyl chloroiodophosphonoacetate ester, R PO CClICO R, respectively. It will also be appreciated that the corresponding bromoiodophosphonoacetate ester can be prepared accordingly by a suitable choice of hypohalite reactants and reaction conditions.

The hypohalogenation reactions of this invention, are normally heterogeneous reactions between two substantially immiscible liquid phases, viz., the phosphonoacetate ester organic phase and an aqueous phase. The aqueous phase is considered the reaction zone. No added electrolyte is necessary, e.g., no electrolyte other than that present as a part of the hypohalite reactant, in the practice of the process of this invention. However, it is preferred that the aqueous phase contain an electrolyte concentration of from about 0.2% to about 75% by weight obtained either from the hypohalite ion and/or from an added electrolyte. Where an electrolyte is to be added the electrolyte used can be a base, such as NaOH or KOH; or a salt, such as NaCl, Na CO K CO NaNO Na 'SO NaC- H O and the like or any other compounds of the general class known as electrolytes which are water-soluble and do not react with the hypohalite ion, e.g., the alkali metal borates, carboxylates and phosphonates. Where an electrolyte containing a halide is used, care should be taken that the electrolyte chosen is not a salt or a halide other than that which is to be added to the phosphonoacetate ester. If this care is not taken, substitution of halides other than the desired halide, which is being reacted with the phosphonoacetate ester, could occur as a competing reaction and could result in a mixture of halogenated phosphonoacetate ester reaction products.

Since the hypohalite ion in aqueous solution exists in equilibrium with hypohalous acid the process set forth above for the preparation of the monohalogenated phosphonoacetate ester and for the dihalogenated phosphonoacetate ester must be conducted above a pH of about 7 to ensure the presence of a sufiicient amount of hypohalite ion for the hypohalogenation. A temperature of about C. to about 100 C. and a reaction time of from about 3 minutes to about 10 hours, depending upon the rate of addition of the reactants, the temperature and the general reaction conditions, are generally used.

In the preferred method of producing the monohalogenated phosphonoacetate ester, a mixture of the aqueous phase and the phosphonoacetate ester organic phase is stirred vigorously. Rapid stirring is essential as this tends to break the organic phase into tiny discrete globules intermixed with the aqueous phase. This agitation of the mixture is continued, while adding to the reaction mixture a compound capable of providing, in the aqueous solution phase, the necessary concentration of an ion selected from the group consisting of 001-, OBr-, and 01-. The term compound here is used in a broad sense to cover both addition of elemental halogen (forming the hypohalite ion in situ) or an alkali or alkaline earth metal hypohalite.

In addition to the procedure described above the hypohalite ion can be generated in the aqueous phase subse quent to the addition of the phosphonoacetate ester or the phosphonoacetate ester can be added rapidly to the hypohalite ion solution. The hypohalite ion can be added directly to the aqueous solution or it can be generated in situ, such as for example, by repeated addition of small amounts of the desired halogen such as liquid bromine, chlorine gas or iodine as a solid or solution. Examples of suitable hypohalite ion compounds include Ca(OCl) Ca(OBr)- KOCl, KOBr, NaOCl, NaOBr, NaOI and KOI.

As has been hereinbefore described the preparation of the monohalogenated or dihalogenated derivative of the trihydrocarbyl phosphonoacetate esters in general is controlled by the ratio of the hypohalite reactant employed to the amount of phosphonoacetate ester used. Either the monohalogenated or dihalogenated phosphonoacetate esters can be obtained by a suitable choice of reaction conditions as described in Quimb et al., supra.

Recovery of the monohalogenated or dihalogenated trihydrocarbyl phosphonoacetate ester products from the reaction mixture can be performed by a cessation of stirring which allows the aggregation of the tiny discrete organic phase globules into one homogenous reacted organic phase. The organic phase can then be readily separated from the aqueous solution and the monohaloor dihalo-phosphonoacetate ester extracted from the organic reaction product by methods old in the art, e.g., chromatography, selective extraction and fractional crystallization.

The monohalogenated and dihalogenated phosphonoacetate esters of this invention are all useful as extreme pressure additives in lubricant compositions, e.g., when used at about the level in a Kendall base SAE 30 mineral oil. The use of these additives in lubricant compositions is more fully disclosed in the copending application of Robert Earl Wann, Denzel Allan Nicholson, and Ted Joe Logan, Ser. No. 762,966, filed Sept. 26, 1968, for Lubricant Composition. This application is incorporated herein by reference.

EXAMPLE I Tri(2-ethyl-1-pentyl) monobromophosphonoacetate T ri(2-ethyl 1 pentyl)phosphonoacetate, 1 mole (434 g.), is placed in a reaction flask at 25 C. The phosphonoacetate is stirred vigorously as a sodium hypobromite solution (1 mole of sodium hypobromite in 300 cc. of water containing 90 g. of Na SO is added slowly. After the addition of the hypobromite, the mixture is stirred at 25 C. for an additional minutes. At this time two layers are formed and the water layer extracted three times with carbon tetrachloride. The carbon tetrachloride extracts are combined with the original product layer, dried over anhydrous sodium sulfate for 15 minutes, filtered and the carbon tetrachloride removed by evaporation. The product, tri(Z-ethyl-l-pentyl) monobromophosphonoacetate, is obtained in about to yield and is about 60% pure.

EXAMPLE II Tri(iso-pentyl) monochlorophosphonoacetate Tri(iso-pentyl)phosphonoacetate, 1 mole (318 g.), is placed in a reaction flask at 25 C. The phosphonoacetate in the reaction flask is stirred vigorously during the addition of 1 mole of sodium hypochlorite in a water solution (74 g. of sodium hypochlorite, 200 cc. of water) to which 200 g. of K 00 has been added. After the addition of the sodium hypochlorite is complete the mixture is stirred at 25 C. for an additional 10 minutes. At this time two layers are formed. The water layer is extracted three times with carbon tetrachloride. The carbon tetrachloride extracts are combined with the original product layer, dried over anhydrous sodium sulfate for 15 minutes, filtered, and the carbon tetrachloride removed by evaporation. The product, tri(iso-pentyl) monochlorophosphonoacetate, is obtained in about 80 to 100% yield and is about 60% pure.

When in the above example, the compounds listed in column 1 below are substituted for the tri(iso-pentyl)- phosphonoacetate on a molar basis and the compounds listed in column 2 below are subsituted for the NaOCl on a molar basis, substantially equivalent results are obtained in that the compounds listed in column 3 below are formed in good yield.

Phosphonoacetate Hypohalite reactant reactant Reaction product Trlpentyl phosphonoacetate NaOI Tripentyl monoiodophosphonoacetate. 2-fluoropeutyl-Z-ehloropentyl- N aOBr 2-fluoropeutyl-2-chloro- 2-bromopentyl phosphonopentyl-2-bromopentyl acetate. monotbromophosphonoac a a. Hexyl(methyl)butyl-lso- NaOCl Hexyl(methyl)butyl-isopentyl phosphonoacetate. pentyl monochlorophosphono acetate. Iso-pentylhexenylbenzyl KOBr Iso-pentylhexenylbenzyl phosphonoacetate. monotbromophosphono- 7,7,7-trichloroheptyl-2-bromo- KOI pentenyl-2,3-dichlorohept- 4,5-dienyl phosphonoat: e.

7,7,7-trlchloroheptyl-2- bromopenteuyl-2,3-dichlorohept4,5-dienyl Tri(Z-methyl-l-butyl) dichlorophosphonoacetate Tri(Z-methyl-l-butyl)phosphonoacetate, 1 mole (380 g.), is placed in a reaction flask with 4 moles g.) of sodium hydroxide in 500 ml. of Water at 0 C. and stirred vigorously. Chlorine, 2 moles (142 g.), are then bubbled into the two phase system. After the chlorineaddition, the mixture is stirred for 10 additional minutes at 0 C. At this time the layers are separated and the aqueous solution is extracted three times with carbon tetrachloride. The carbon tetrachloride extractions are combined with the original organic layer and dried over anhydrous sodium sulfate for several minutes. The product layer is filtered and the carbon tetrachloride is removed by evaporation. The product, tri(2-methyl-l-butyl) dichlorophosphonoacetate is obtained in a 80-l00% yield at about 90% purity.

EXAMPLE IV Tripentyl dibromophosphonoacetate Tripentyl phosphonoacetate, 17.2 g. (0.044 mole) was added to a 2 liter flask containing 0.098 mole of NaOBr (about 12% excess) in an aqueous system containing 500 cc. of water at a pH of about 11. The mixture was reacted for 10 min. at to C. with vigorous stirring. Several chloroform/water extractions were made and the com bined extracts dried over anhydrous sodium sulfate. The extractions were filtered to remove the sodium sulfate, and the excess chloroform was removed by evaporation. A colorless liquid was obtained and Was identified as the tripentyl ester of dibromophosphonoacetic acid having the following analysis:

Calc.: C, 40.02%; H, 6.5%; P, 6.1%; Br, 31.5%; mol. wt., 508. Found: C, 40.5%; H, 6.8%;P, 5.7%; Br, 36.0%; mol. wt. 500.

NaOI can be substituted for the NaOBr used in the above reaction to prepare the tripentyl diiodophosphonoacetate ester. Similarly other trihydrocarbyl phosphonoacetate esters can be substituted for the tripentyl phosphonoacetate ester used above to prepare the corresponding trihydrocarbyl dibromophosphonoacetate esters, e.g., triphenyl phosphonoacetate, tri(methyl)phenyl phosphonoacetate, tripentyl phosphonoacetate, tri-m-chlorobenzyl phosphonoacetate, tri(bromo)phenyl phosphonoacetate, tri[(chloromethyl)phenyl1 phosphonoacetate, tri- [(chlorophenyl)methyl] phosphonoacetate, tri(5-iodopentenyl) phosphonoacetate, and tri(nitrophenyl) phosphonoacetate.

When in Example IV the following compounds in column 1 below are substituted for the tripentyl phosphonoacetate used above and when the hypohalite sources listed in column 2 below are substituted for the sodium hypobromite used, substantially equivalent results are obtained in that the reaction products listed in column 3 below are formed.

Phosphonacetate Hypohalite reactant reactant Reaction product Trlhexyl phosphonacetate- KOI Trihexyl diiodophosphonoacetate. 3-chloropentyl-Z-chlorohexyb NaOCl 3-ohloropentyl-2-chloroheptyl phosphonoacetate. hexylheptyl d1 chlorophosphonacetate. Di-iso-pentylpentyl phos- KOBr Di-iso-pentylpentyl phonoacetate. dibromophosphonoacetate. Dt(6,6-difluorohexyl) bromo- KOBr Di(6,6-difiuorohexyl) phenyl phosphonoacetate. bromophenyl dibrornophosphonoaeetate. Tri(hepta-2,4-d1euyl) Ca(OBr) 2 Tri(hepta-2,4-dienyl) phosphonoacetate. dibromophosphonoacetate. 3-chloropentenyl-o-brom0- N a0 Cl 3-chlorop entenylobromobenzyl (methyDphenyl benzyl(methyl)phenyl phosphonoacetate. dichlorophosphonoacetate. Trlpentyl phosphono- C12/N aOH Tripentyl dichlorophosacetate. phonoacetate. Tribenzyl phosphono- KOI Tribenzyl diiodophosacetate. phone-acetate. Triphenyl phosphono KOBr Triphenyl dibromophosacetate. phonoacetate. B enzyl (methyl) ph enyl- C a( 01) 2 B enzyl (methyl) phenyl- (chlorom ethyl) phenyl (ch loromethyl) ph enyl phosphonoacetate. 1diiodophosphorloacea e. Tri(chlorophenyl) phos- NaOBr Tri(chl0r0phenyl) diphonoacetate. bromophosphonoacetate.

The monoand dihalogenated phosphonoacetate esters disclosed in Examples I-V are effective extreme pressure additives when used at the 5% level in e.g., a Kendall base SAE 30 mineral oil.

What is claimed is:

1. A halogenated phosphonoacetate ester having the formula wherein each R is selected from the group consisting of aryl, alkaryl, arallryl, haloaryl, haloalkaryl, haloaralkyl and nitroaryl groups having from 6 to 7 carbon atoms, wherein each X is selected from the group consisting of hydrogen, bromine and iodine and wherein both Xs are not simultaneously hydrogen.

2. The compound of claim 1 wherein one X is hydrogen and the other X is selected from the group consisting of bromine and iodine atoms.

3. The compound of claim 1 wherein each X is selected from the group consisting of bromine and iodine atoms.

4. The compound of claim 2 wherein one X is hydrogen and the other X is bromine.

5. The compound of claim 3 wherein each X is bromine.

References Cited UNITED STATES PATENTS 2,599,761 6/1952 Harman et al. 260941 FOREIGN PATENTS 530,327 l/1955 Belgium 260-941 JOSEPH REBOLD, Primary Examiner A. H. SUTTO, Assistant Examiner US. Cl. X.R.

Dedication signee, The Pmcter cfi Gamb le Company. Hereby dedicates t0 the Public the entire remaining term of said patent.

[Ofim'al Gaze-tie June 73, 1972.] 

